#include<bits/stdc++.h>
using namespace std;
int main(){
	queue<int>q;
	cout << q.empty() << endl;
	for(int i = 1 ; i <= 5 ; i++){
		q.push(i);
	} 
	q.push(10);
	cout << q.size() << endl;
	cout << "front: " << q.front() << endl;
	cout << "back: " << q.back() << endl;
	q.pop();
	cout << "front: " << q.front() << endl;
	cout << "back: " << q.back() << endl;
	while(!q.empty()){
		q.pop(); 
	}
	cout << q.empty() << endl;
	return 0;
}
